Karl Schroeder: one-way tickets to Mars are a cost issue, not a risk issue

Paul Raven @ 22-09-2009

exploding rocketWe’ve mentioned the one-way option for Mars missions here a few times recently, the latest being in response to the Krauss op-ed in the New York Times. Earning himself his second Futurismic mention in as many days, Karl Schroeder tears down the “poisonous meme” that claims the journey to Mars is too dangerous – the reality is that it’s too expensive.

The objections all sound reasonable:  too much radiation!  Too far away!  Zero gravity is too debilitating!  Too expensive!

All of these objections are true, while at the same time they’re all wildly wrong, and largely for the same reasons.  In fact they’re all true only if getting from Earth to orbit remains as expensive as it is now.

Consider the seemingly insurmountable problem of radiation that Krauss complains of in his piece.  What’s the solution to radiation?  Shielding.  Is shielding a spacecraft impossible, or even difficult?  No, actually it’s easy.  Two meters of water around the crew cabin are enough to solve the problem of radiation in the inner solar system.  The problem is not the shielding; it’s the cost of shipping the water up to orbit that is the problem.

Ditto for, oh, let’s say zero gravity.  No astronaut should ever have to put up with zero gravity for more than a day or two at a time; the simple solution to the debilitating effects of freefall is to spin the spacecraft.  To do it in a manner comfortable to to the astronauts, you need a long boom arm, which might be heavy and awkward to lift from Earth.  The point is, the solution is easy.

Too far away?  If a space voyage is going to take months or years, there are two simple solutions:  send the ship faster, by using more propellant; or bring along more supplies.  Both of these solutions are primarily constrained by the cost of bringing stuff up from Earth.

That cost is, of course, the cost of old-school 1960s vintage chemical rocketry – $10,000 for every kilogram of stuff you want to get into orbit. Schroeder lists a number of alternatives, some of which you’ll have read about here or elsewhere: magnetic accelerators, laser propulsion launchers and so on… all with much lower to-orbit costs, all within the reach of NASA budgets – if they abandoned rocketry.

The question stands, though: given that NASA is well aware of its own budgetary problems, why is it clinging to such dated and inefficient methods? Is it for the prestige, the showiness, the rocket’s red glare? (You have to admit, a Space Shuttle launch is pretty impressive to watch… when it works.) [image by jurvetson]

But back to Schroeder:

Space is only a costly and dangerous destination if you insist on using 1960s technology to reach it.  Once NASA–or more likely the private sector–finally abandons that route, what was impossible will become easy.  —I only fear that the meme of space’s inaccessibility will prevent us from ever building the launch infrastructure that will prove it wrong; at this point, the meme looks like it’s turning into a self-fulfilling prophecy.

That would be a sad thing – to turn our backs on space, not because it was genuinely impossible, but because we’d allowed ourselves to be convinced that it was.

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One Response to “Karl Schroeder: one-way tickets to Mars are a cost issue, not a risk issue”

  1. jon says:

    The Iraq War has cost the USA alone $12billion a month, and people argue that space exploration is too expensive. Sad that humans can always dig up some cash for fighting, but not so much for advancement.